Fields of the Invention
The present invention relates to a system and a method for temperature sensing of three-dimensional integrated circuits, especially to a system and a method for multiple temperature sensing of a plurality of chip layers of three-dimensional integrated circuits. In the system, temperature of various points at different chip layers is conducted to the same chip layer by Through Silicon Vias (TSVs) to be measured and calibrated. The design complexity and the implementation cost of the temperature sensing system can be reduced significantly.
Descriptions of Related Art
The three-dimensional integrated circuit (3D IC) can solve the problems of two-dimensional system-on-chip (SoC) by Through Silicon Vias (TSVs). However, one of the big challenges facing 3D IC is how to remove the heat generated by various chip layers to keep a high performance chip temperature within the system and reliability constraints and prevent hot spots. Thus, a temperature sensing system is getting important in the 3D IC. The 3D IC includes different circuit types. In order to optimize cost and performance, different chip layers are fabricated by different manufacturing techniques. As a result, different chip layers have different temperature sensors and the design complexity of the temperature sensing system is increased dramatically. Moreover, different temperature sensors have different calibration mechanisms. Additional digital or analogue signals are also required and transmitted by Through Silicon Vias for calibration. Thus the calibration of all temperature sensors in the temperature sensing system is getting quite difficult and a lot of Through Silicon Vias may be required. Thus for companies and researchers dedicated to 3D IC related temperature sensing technology, it is an important issue to invent a temperature sensing system for 3D ICs with low cost and low complexity in which temperature sensors are arranged at different chip layers of 3D IC. Dynamic temperature control mechanism is also used to ensure reliability of the system. Thus temperature variance of the 3D IC caused by changes of temperature, manufacturing processes or voltage can be calibrated by the temperature sensing system.